Upregulation of miR-125b, miR-181d, and miR-221 Predicts Poor Prognosis in MGMT Promoter-Unmethylated Glioblastoma Patients

Objectives: To evaluate the prognostic values of microRNAs (miRNAs) in glioblastoma, and to see if there is an association between miRNAs and MGMT promoter methylation status. Methods: We collected paraffn blocks from resection specimens from 114 glioblastoma patients who had received temozolomide treatment and radiotherapy. Realtime quantitative PCR was performed to determine the expression levels of fve miRNAs. Results: Upregulation of miR125b-5p, miR181d-3p, miR221-3p, miR-222-3p, and miR224-5p was observed in 13.2%, 5.3%, 12.3%, 32.5%, and 78.9% of the cases, respectively. The expression level of miRNAs was not signifcantly different in tumors with MGMT promoter methylation vs tumors without such methylation. Upregulation of miR125b-5p, miR181d-3p, or miR-221-3p was signifcantly associated with shorter survival in MGMT-unmethylated glioblastoma patients. Conclusions: MiR125b-5p, miR181d-3p, and miR221-3p are useful in predicting poor prognosis in patients with MGMT-unmethylated glioblastomas.